%0 Journal Article
%T Expression of the Human Soluble Interleukin 4 Receptor in Methylotropic Yeast<br>人可溶性白介素-4受体(sIL-4R)在甲醇酵母中的表达
%A ZHANG YongHU JianLI Yuan
%A <br>张勇
%A 胡箭
%A 李元
%J 生物工程学报
%D 2004
%I 
%X Interleukin-4 (IL-4) is a pleiotropic cytokine which plays a pivotal role in shaping immune responses. IL-4 mediates important proinflammatory functions in asthma, including the IgE isotype switch. IL-4 exerts its biological effects through binding to its receptor (IL-4R) complex, with the alpha chain as the high affinity binding subunit. Soluble IL-4R lacks the transmemberane and cytoplasmic domains, so it cannot induce cellular activation. By acting as a decoy to circulating IL-4 and neutralize its activity, its high specificity and affinity make it ideal as an IL-4 antagonist. Some companies have embarked the clinical research for asthma treatment with the sIL-4R and the result revealed well therapeutic effect. With RNA extracted from human monocyte as the template, The sIL-4R cDNA encoding the extracellular domain of IL-4R a chain was obtained by RT-PCR. Compared with the sIL-4R encoding sequence in GenBank, the nucleotide sequencing analysis indicated that there was a A-->G mutation at 148bp and the mutation caused Ile-->Val at 50th amino acid. According to the references, numerous polymorphisms have been identified in the IL-4R gene and the Ile50Val was the only known extracellular variant of human IL-4R. Then the recombinant vector pPIC9K/sIL-4R was constructed, linearized and introduced into Pichia pastoris GS115 by electroporation. The recombinant sIL-4R was identified by SDS-PAGE, Western blot and Ligand binding blot. The SDS-PAGE and Western blot analysis showed that the apparent molecular weight of expressed sIL-4R was about 30kD. And the Ligand binding blot analysis indicated the expressed sIL-4R had the biological activity. The sIL-4R, which had the biological activity, was successfully secretorily expressed in the Pichia pastoris (GS 115).
%K human soluble interleukin 4 receptor(sIL-4R)
%K Pichia pastoris<br>人可溶性白介素-4受体
%K 白细胞介素-4
%K IL-4
%K 甲醇酵母
%K 表达
%K 生物学活性
%K 变态性炎症
%K 哮喘
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=90BA3D13E7F3BC869AC96FB3DA594E3FE34FBF7B8BC0E591&jid=A66E90C274451689E69F6F0291467824&aid=E71E29E4484BB7AA&yid=D0E58B75BFD8E51C&vid=A04140E723CB732E&iid=0B39A22176CE99FB&sid=2BA123C6EB9D54C2&eid=974CBB04624305A1&journal_id=1000-3061&journal_name=生物工程学报&referenced_num=1&reference_num=30